gistfile1.txt

<?php

//loop er bahire 

$a = 0;
$active_class = '';

loop er bitore 

while (condition goes here):

if(0 == $a){
  $active_class = 'active';
}

<div class='some class <?php echo esc_attr($active_class)?>'>
markup goes here
</div>


 $a++;
endwhile;